As a measure for imparting the characteristics possessed by a siloxane resin such as water resistance, weather resistance and the like to an acrylic resin or other resins, attempts have been made to fix an organosiloxane, through a chemical linkage, to a compound bearing radically polymerizable unsaturation bonds. For example, Japanese Patent Application Kokai No. 61126/79 discloses methyl di (trimethyl siloxy) silyl propyl glycerol methacrylate which is prepared by the addition reaction of organo polysiloxane containing epoxy groups and methacrylic acid and is used as a monomer for a resin which is excellent in oxygen permeability and hydrophilic properties and hence is useful as a contact lens material; Japanese Patent Application Kokai No. 63200/79 discloses an organo polysiloxane containing acryloyloxy groups which has the characteristic of being cured in a short period of time under irradiation condition and which is prepared by the reaction of organo polysiloxane containing amino groups and glycidyl acrylate; Japanese Patent Application Kokai No. 22325/81 discloses a process for the preparation of polymerizable organo polysiloxane by the reaction of organo polysiloxane containing epoxy groups and an acrylate; and Japanese Patent Application Kokai No. 180667/82 discloses a process for the preparation of polymerizable organosiloxane by the reaction of trialkyl chlorosilane and hydroxyalkyl acrylate. However, they are not always of satisfactory in respect to reaction speed and reaction yield and hence are not economical in an industrial scale production of silicon modified monomers. Furthermore, in these methods, since the principal objects are the mere introduction of hydrophobic siloxane bonds to polymerizable monomers, the actual use of thus obtained monomers has been rather limited to a narrow range as, for example, in the preparation of particular resins which are to be used in specific areas requiring the characteristic properties of said siloxane bonds only, as, the oxygen permeability of these resin making them useful in contact lens or the like. Under the circumstances, these present inventors, having endeavored to discover a novel class of polymerizable monomers containing silicons bearing functional groups or bonds and as well as siloxane bonds, have succeeded in establishing a method for the preparation of class of monomers represented by the formula: ##STR6## wherein R.sup.1 is a substituted or unsubstituted monovalent hydrocarbon residue; R.sup.4 is a substituent directly bonded to a silicon atom and is selected from a substituted or unsubstituted alkylene or a substituted or unsubstituted alkylene containing hetero atoms, the alkylene being attached directly to a silicon atom; R.sup.3 is hydrogen or methyl group;A is a direct bond, ##STR7## or a substituted or unsubstituted phenylene group; m and n each is a positive integer which will fulfil the requirement of 2.ltoreq.m+n.ltoreq.4, comprising reacting a hydroxyl containing silicon compound of the formula: ##STR8## wherein R.sup.1, R.sup.4, m and n have the same meanings as defined hereinbefore, and a polymerizable isocyanate compound of the formula: ##STR9## wherein R.sup.3 and A have the same meanings as defined hereinbefore, and have applied for a patent on it at the same day with the present patent application (i.e. Japanese Patent Publication (unexamined) No. 298595/87). Such monomers may be homopolymerized or copolymerized with other vinyl monomers to provide various vinyl polymers containing silicons. It is, therefore, an object of the invention to provide a novel class of vinyl polymers containing silicons and bearing urethane bonds as well as siloxane bonds, which are derived from said polymerizable monomers containing silicons and are specifically useful in paints, optical lenses and other various industries. An additional object of the invention is to provide an advantageous method for the preparation of said vinyl polymers.